Especially in the field of motocross competition, but also in other vigorous activities, there is the need to protect the shins, and frequently also the knees, against impact by fixed, moving, or flying objects. In motocross operations, flying objects such as gravel, rocks, and debris regularly strike the knees and shins of the rider. Shin guards and knee guards are regularly and routinely worn to protect the rider from injury. Of course ths is not a situation limited to motocross alone. Hockey players represent yet another example of persons who require protection for these parts of the body.
However, motocross riders do present a rather special situation because of the frequency with which they change their posture. Riding a motorcycle vehicle over broken ground or a complicated course involves very frequent changes of posture to compensate for imbalance of the machine and rider, for changing side loads caused by change of forward direction, and for climbing or riding down slopes of varying complexity. All the while, full coverage of the knee and shin is required while the rider moves from a crouched (seated) to a standing posture, and to postures in between.
This raises considerable complications, because when the leg bends at the knee, the linear length to be protected changes. This fact is known by any person who wears a pair of tight pants. It is not an agreeable solution merely to provide stretchable material at the knee, because continuous protection of an agreed thickness or quality is needed. For this reason, it is known to provide a shell-like knee protector, and a shell-like shin protector pivoted together for hinging action, with an overlap of the two so that a gap between them does not exist.
The above would appear to be a suitable solution to the problem, because both the knee and shin are protected at all times against impacting objects. However, and rather surprisingly, this seemingly-suitable solution itself presents problems of its own.
Offhand, one would surmise that a person who indulges in a sport which involves violent maneuvers, substantial varying forces, and routine exposure to flying objects, would not look for comfort in his protective equipment, or be distracted by discomforts which would ordinarily be considered minor compared to the discomfiture that is endured merely by being on board a vehicle that is undergoing such severe operating conditions. But such is not the case. To the contrary, even champion riders will testify that long-continued minor discomforts, which might at the most cause a rash or abrasion, can be sufficiently distracting as to reduce the rider's performance by a small but important degree--one which conceivably could amount to the difference betwen championship or winning performance, and merely excellent performance. Also, when the riding is done for recreation rather than for competition, the elimination or lessening of such distractions or discomforts makes the sport much more agreeable.
The problem with the existing pivoted--together knee and shin protectors is that their pivot line is normal to both the thigh protector and to the shin protector, and thereby assumes that the shin bone and thigh rotate in a common plane. As a consequence, the two parts pivot in the same vertical plane. The problem is that the human joint is not constructed that way, and a flexure of at least 90 degrees is needed.
A person whose legs are anthropomorphically formed to the standard, standing with his thighs normal to the ground finds that his shin bones form an acute angle between them at the knees of about 14 degrees. The shin bone then pivots in a frusto-comical pattern, rather than in a plane. As a consequence, a shin protector which moves in a different mode, such as in the same plane as the thigh bones, will chafe the riders's leg. While padding can be provided to lessen the discomfort, such padding adds undesirable bulk and weight to the rider's competitive disadvantage, and does not solve the problem.
It is preferable for the knee and shin protectors to follow the body part with which they are associated. One solution, of course, is to mount each protector independently of the other. But this requires straps or other means to keep them in place, and it is quite possible that they will become separated or dislodged, so a to expose the rider to risk. A reliable, constant and structural pivotal joinder of the parts is much better and safer.
It is an object of this invention to provide a guard wherein the parts are pivotally joined, but pivot so that they follow the respective body element without substantial chafing.